Skip to main content.

Smithsonian National Museum of Natural History


Square cushion-cut orange clinohumite weighing 21.39 ct.
Photo by Ken Larsen. Click to zoom.
Catalog Number NMNH G11405-00
Locality Tajikistan
Weight 21.39 ct

Purchased with funds from the Tiffany & Co. Foundation in 2011.

Clinohumite is a magnesium silicate commonly found as tiny indistinct grains. However, large euhedral crystals are sought after by collectors and can be cut into beautiful gemstones. Clinohumite is transparent with a glassy luster and can be found in shades of yellow, orange, red or brown. It is sometimes confused with hessonite and spessartine garnets. Gems over a few carats are rare, and due to its brittleness and rather low hardness (6 on the Mohs scale), clinohumite is mainly a collector’s stone. To date, only two sources of gem-quality material are known: the Pamir Mountains of Tajikistan and the Taymyr region of northern Siberia, Russia. This vivid yellowish-orange gem weighs 21.39 carats and is a modified cushion cut. It is the largest and finest clinohumite in the National Gem Collection.


Landscape mode is not currently supported for this website